Fireproofing and weather-resisting paint



I06. COMPOSITIONS,

COATING OR PLASTIC.

rem" OFFICE.

NEVIL MONROE HOPKINS, OF NEW YORK, N. Y., ASSIGNOR TO THE BURNOT FIRE-PROOFIQNG PRODUCTS, INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

FIREPROOFING AND WEATHER-RESIS'IING PAINT.

N0 Drawing. Application filed July 1, 1922, Serial No. 572,323. RenewedMay 29, 1925.

The present invention relates to fireproofing and Weather resistingpaint, designed not only to fireproof combustible substances such aswood, wood fibre, millboard, pasteboard, and strawboard, and other denseor porous or partially porous inflammable or combustible substances, butto resist the action of the elementsthat is rain and sun, in theiraction of alternately wetting, washing and drying out and repeatedwetting, washing and drying out, throughout the months and seasons ofthe year.

F or a vehicle I may use a tung oil, or a linseed oil, either raw orboiled, or a mixture of tung oil and linseed oil, either raw or boiled,or their equivalent, adapted to oxidize into a waterproof adherent film,and with the addition of the customary turpentine and Japan dryer ortheir equivalents in solvent or dryer.

I grind into this oil or mixture of oils or their equivalent withthe-turpentine and Japan dryer or their equivalent, the several pigmentsnecessary to secure good hiding power, and the chemical body or bodiesadapted to prevent or delay the ignition of wood, or other combustiblebody over which the paint is spread.

I have found it highly desirable in the practical manufacture of such afire and Weather resisting paint to reduce the chemical substance orsubstances chosen to retard ignition, to the finest practicable state ofsubdivision. I find this exceedingly fine grinding of the fire retardantsubstances necessary in order that the protective film will not bepunctured by minute crystal points which would in time dissolve away andleave minute; pin hole openings through which water from repeated stormscould enter and undermine the substance of the paint.

I am aware of the fact that many attempts have been made toproduce asatisfactory rain and sun resisting and also a fire resisting paint andthat expensive insoluble borates such as zinc borate and lead boratehave been used together with other insoluble chemical compounds as wellas with soluble chemical compounds such as ammonium phpsphaje, ammoniumsulphate, boric acid,

etc. These expensive insoluble borates as well as boric acid melt downreadily to form a more or less efficient glass or glaze which surroundsand covers the fibres as well as the surface of the wood, therebycutting off more or less efficiently the oxygen of the air necessary tosupport combustion after the kindling temperature has been attained asthe result of impinging flames or other igniting influences.

Although paints fabricated from these expensive chemical substances maybe What have been termed more or less efiicient, they have been far fromsatisfactory as fire retardants.

In my fireproof paint the results in comparison have been astoundinglysuperior. In the fireproof paint of my present invention I find that thesparingly soluble and exceedingly cheap sodium biborate, or ordinaryborax of commerce (very sparingly soluble at ordinary temperatures)grinds into the oil or compound vehicle as described together with suchconventional pigments as white lead, zinc oxide, finely groundasbestine, barytes, etc., to form not only a paint of superior andexceedingly high fire resisting properties, but of exceedingly good rainand sun resisting qualities. But in practice I prefer to apply over sucha priming coat or coats one or more coats of a superior weatherresisting paint.

I have proven that the impalpable borax powder provided by theexceedingly fine state of subdivision, 100 mesh or finer, to which Ihave reduced my borax when worked into a cream and subsequently added tothe tung oil or linseed oil vehicle with the conventional pigments, addsmarkedly to the difliculty of dissolving the borax out by water.

Borax when very finely ground in With a suitable oil or oils asdescribed, not only resists washing out to a remarkable extent throughthe action of rain when used as a paint as above, but especially is thistrue when it is protected with a good weather proof paint, as abovedescribed. When a flame is impinged upon the surface of a combustiblebody protected by my paint containing a large percentage of borax, thelatter swells immediately and profusely causing the borax to produce aheat insulating barrier. Later,'upon more intense heating, this barrieror coating gives up its water of crystallization to such an extent thatit is exceedingly difiicult to ignite the combustible body over which itis spread. Ultimately upon more prolonged intense heating the coatingfuses down into a glass whlch impregnates the fibres of the combustiblesubstance and gives fire resisting results infinitely superior to theexpensive zinc borate or lead borate.

That is, the double action of borax in first swelling prolificly andthereby providing a heat insulating barrier on the one hand, and then informing an oxygen isolating glaze on the other hand, produces remarkablefireproofing results. I have furthermore learned that the addition ofsome zinc borate or lead borate or a mixture of the two and also of somepowdered glass assists in the malting down or fluxing of the borax massafter its swelling period is over and its water of crystallization isgiven up, although the mixture of these substances with borax is notabsolutely necessary in the fabrication of a very efficient paint.

In order to insure prolonged resistance to the elements such as rain,sun, snow, drying out, wetting again, freezing, thawing, drying outagain, etc., etc., I prefer to apply one or more coats of the fireresisting paint as above described and to give to this paint aprotective coat of ordinary paint containing the conventional vehilessuch as tung oil and linseed oil and the conventional pigments such aswhite lead, basic sulphate of lead, and zinc oxide ground in the vehicleoils with turpentine and suitable dryer. I also prefer to cover in somecases the fire retardant paint with a protecting paint consisting of anoil or oils such as tung oil or linseed or their equivalent andconventional pigments such as white lead and zinc oxide but in adding acertain percentage of varnish.

IVith this combination covering thesurface to be protected, I secureefficient results, the under coat or coats containing the borax orsodium biborate sparingly soluble in water at ordinary weathertemperatures, and the outer coat or coats consisting of a good andsuitable water shedding paint.

Having described my invention and the principle thereof, I am givinghere a typical formula with proportions which may be more or less variedfor preparing one gallon of my borax paint:

5 pounds borax.

1 pound white lead.

1 pound zine oxide.

5 ounces asbestine. 3 ounces barytes.

1 ounce lead borate.

1 ounce zinc borate.

3 pints linseed oil (boiled).

1 pint treated tung oil.

% pint Japan dryer.

pint varnish.

Although I have found in practice that a gallon of paint made upon theabove proportions gives most efficient results, it is understood ofcourse, that these proportions may be somewhat varied without departingfrom the spirit of my invention and without unduly impairing theefficiency of the product. Having described my invention, I claim: 1.The herein described fire proofing and weather resisting paintcomposition, the

same comprising borax, white lead, zinc oxide, asbestine, barytes, leadborate, zinc borate, and an oxidizing oil in substantially theproportions specified.

2. The herein described composition of matter including oxide of zinc,basic lead carbonate, borax, asbestine, barytes and borates of lead andzinc, all substantially in the proportions specified and mixed with aliquid vehicle containing linseed oil.

3. A fire resisting paint including in its composition, a plurality ofpigments mixed in a vehicle including oil, said pigments including boraxreduced to an impalpable powder and in quantity in excess of 40 per centby weight of the total pigment content so as to form when applied in theform of a coating on surfaces of wooden articles an oxygen isolatingglaze under exposure to heat.

4. A fire resisting paint including in its composition, a plurality ofpigments mixed in a vehicle including oil, said pigments including boraxreduced to an impalpable powder and in quantity sufficient to form whenapplied in the form of a coating on surfaces of wooden articles anoxygen isolating glaze under exposure to heat, said paint including alsoa flux-promoting agent so as to aid in the formation of the oxygenisolating glaze.

5. A fire resisting paint including in its composition, a plurality ofpigments mixed in a vehicle including oil, said pigments including boraxreduced to an impalpable powder and in quantity sufiicient to form whenapplied in the form of a coating on surfaces of wooden articles, anoxygen isolating glaze under exposure to heat, said paint including alsoa borate as a flux-promoting agent for the borax.

6. A fire resisting paint including in its composition a plurality ofpigments mixed in a vehicle including oil, said pigments including morethan 50 per cent by weight of borax reduced to an impalpable powder.

7. A fire resisting paint including in its composition a plurality ofpigments mixed in a vehicle including oil, said pigments including morethan 50 per cent by weight of I06. COMPOSITIONS, 1 COATING OR PLASTIC.

borax reduced to an impalpable powder, and in excess of 10 per cent eachby weight of less than 5 per cent by weight of a bomte. basic leadcarbonate and zinc oxide.

8. A fire resisting paint including in its Signed at New York city, inthe county 10 composition a plurality of pigments mixed of New York andState of New York this 5 in a vehicle including oil, said pigments in-30th day of June, A. D. 1922.

eluding more than 50 per cent by weight of borax reduced to anilnpalpable powder, and N EVIL MONROE HOPKINS.

